The deal is intended to bolster a Phillies rotation that currently includes Cole Hamels, Cliff Lee and Jerome Williams. It will pay Harang a base salary of $5 million, in addition to bonues.
Harang signed with the Atlanta Braves last season, where he went 12-12 in 33 starts with an ERA of 3.57 through 204.1 innings pitched.
In a statement, Phillies general manager Ruben Amaro Jr. noted the depth that Harang's signing brings to the Philadelphia rotation for the 2015 season.
"Aaron brings a wealth of experience and durability to our rotation," general manager Ruben Amaro Jr. said. "He had a very solid season for the Braves last year and will complement the left-handers in our rotation nicely."
The 36-year-old Harang is set to enter his 14th season in Major League Baseball, and will enter the 2015 season with an overall record of 122-128 with a 4.21 ERA in 358 games.
Prior to joining Philadelphia, Harang has spent time with the Oakland Athletics, Cincinnati Reds, Sand Diego Padres, Los Angeles Dodgers, Seattle Mariners, New York Mets and the Braves. With Harang's signing, one spot remains open on the Phillies 40-man roster.
The Phillies finished 2014 with a 73-89 record and in 5th place in the NL East.
- Jack Jorgensen